MESOSCALE DISCUSSION 1399
   NWS STORM PREDICTION CENTER NORMAN OK
   1235 PM CDT SUN JUN 26 2011
   
   AREAS AFFECTED...PORTIONS NRN SD AND SRN ND.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 261735Z - 261900Z
   
   WW BEING DRAWN FOR NRN NEB/SRN SD ALSO MAY INCLUDE SRN PORTIONS OF
   THIS AREA...WITH POTENTIAL FOR WIDELY SCATTERED SVR GUSTS/HAIL IN
   CORRIDOR NEAR SFC FRONTAL ZONE OUTLINED BELOW.  TSTM W OF FRONT
   PRODUCED MEASURED 63-KT GUST AT 2WX NWRN SD...PENETRATING THROUGH
   RELATIVELY STABLE BOUNDARY LAYER CHARACTERIZED BY 50S F SFC TEMPS.
   
   SFC MESOANALYSIS SHOWS QUASISTATIONARY FRONT BETWEEN JMS-RDR THEN
   SWWD BETWEEN MBG-PIR...BECOMING DIFFUSE AMIDST ONGOING CONVECTION
   AND PRECIP.  THERMALLY STRONGER FRONTAL SEGMENT THEN IS ANALYZED
   WSWWD AND WWD ACROSS NRN BLACK HILLS REGION TO NERN WY...WHILE
   INITIAL/WEAKER SEGMENT WITH PRONOUNCED WIND SHIFT IS EVIDENT NEAR
   AIA THEN SSWWD TO WRN PORTIONS CO/NEB BORDER.  REF MESOSCALE
   DISCUSSION 1938 FOR AREAS S OF ABOUT I-90.  FARTHER N...CORRIDOR OF
   FAVORABLE NEAR-SFC BASED INSTABILITY NARROWS NWD ACROSS NRN SD TO
   S-CENTRAL/SERN ND NEAR FRONT...WITH MLCAPE GENERALLY IN 500-1500
   J/KG RANGE BASED ON MODIFIED RAOBS AND RUC SOUNDINGS.  EFFECTIVE
   SHEAR MAGNITUDES AROUND 40 KT MAY SUPPORT SOME SVR THREAT...ALSO NOT
   AS WELL-ORGANIZED AS FARTHER S...BUT WITH OCNL HAIL/GUSTS STILL
   POSSIBLE.  MLCIN SHOULD CONTINUE TO INCREASE WITH EWD EXTENT ACROSS
   ERN DAKOTAS INTO WRN MN...WITH DIABATIC DESTABILIZATION
   SUBSTANTIALLY SUBDUED BY EXTENSIVE CLOUD COVER EVIDENT IN VIS
   IMAGERY.
   
   ..EDWARDS.. 06/26/2011
   
   
   ATTN...WFO...FGF...ABR...BIS...UNR...
   
   LAT...LON   44120188 45800176 46460007 46999692 45099860 43949936
               44120188